dbseer.middleware.packet.MiddlewarePacketDecoder.java Source code

Introduction

Here is the source code for dbseer.middleware.packet.MiddlewarePacketDecoder.java

Source

/*
 * Copyright 2013 Barzan Mozafari
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *     http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */

package dbseer.middleware.packet;

import com.esotericsoftware.minlog.Log;
import io.netty.buffer.ByteBuf;
import io.netty.channel.ChannelHandlerContext;
import io.netty.handler.codec.ByteToMessageDecoder;

import java.util.List;

/**
 * Created by Dong Young Yoon on 12/2/15.
 */
public class MiddlewarePacketDecoder extends ByteToMessageDecoder {
    @Override
    protected void decode(ChannelHandlerContext ctx, ByteBuf buf, List<Object> out) throws Exception {
        if (buf.readableBytes() < 8) {
            Log.debug(this.getClass().getCanonicalName(), "buf less than 8 bytes");
            return;
        }

        buf.markReaderIndex();
        int header = buf.readInt();
        int length = buf.readInt();

        if (buf.readableBytes() < length) {
            buf.resetReaderIndex();
            Log.debug(this.getClass().getCanonicalName(),
                    "readable bytes less than length = " + length + " and header = " + header);
            return;
        }
        String log = "";
        Log.debug(String.format("len = %d, readable = %d", length, buf.readableBytes()));

        if (length > 0) {
            byte[] readBuf = new byte[length];
            buf.readBytes(readBuf);
            log = new String(readBuf, "UTF-8");
        }

        out.add(new MiddlewarePacket(header, length, log));
    }
}